test: time_utils: fix negative test

On systems with newer libc, the previously failing time conversion test
is now successful:

../redfish-core/ut/time_utils_test.cpp:27: Failure
Expected equality of these values:
  fromDurationString("P99999999999999999DT")
    Which is: (8-byte object <00-A4 D9-92 19-D6 A8-56>)
  std::nullopt
    Which is: 1-byte object <00>

Add some more 9s to make the test fail again.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib7d336ef4f334bd2263c408bd0c333f20a908e39
diff --git a/redfish-core/ut/time_utils_test.cpp b/redfish-core/ut/time_utils_test.cpp
index 86174ba..d03c316 100644
--- a/redfish-core/ut/time_utils_test.cpp
+++ b/redfish-core/ut/time_utils_test.cpp
@@ -24,7 +24,7 @@
     EXPECT_EQ(fromDurationString("P1T"), std::nullopt);
     EXPECT_EQ(fromDurationString("PT100M1000S100"), std::nullopt);
     EXPECT_EQ(fromDurationString("PDTHMS"), std::nullopt);
-    EXPECT_EQ(fromDurationString("P99999999999999999DT"), std::nullopt);
+    EXPECT_EQ(fromDurationString("P9999999999999999999999999DT"), std::nullopt);
     EXPECT_EQ(fromDurationString("PD222T222H222M222.222S"), std::nullopt);
     EXPECT_EQ(fromDurationString("PT99999H9999999999999999999999M99999999999S"),
               std::nullopt);